Allow model config to preprocess the vae state dict on load.

comfy/sd.py

@@ -448,6 +448,7 @@ def load_checkpoint_guess_config(ckpt_path, output_vae=True, output_clip=True, o
 
     if output_vae:
         vae_sd = comfy.utils.state_dict_prefix_replace(sd, {"first_stage_model.": ""}, filter_keys=True)
+        vae_sd = model_config.process_vae_state_dict(vae_sd)
         vae = VAE(sd=vae_sd)
 
     if output_clip:

comfy/supported_models_base.py

@@ -56,6 +56,9 @@ class BASE:
     def process_unet_state_dict(self, state_dict):
         return state_dict
 
+    def process_vae_state_dict(self, state_dict):
+        return state_dict
+
     def process_clip_state_dict_for_saving(self, state_dict):
         replace_prefix = {"": "cond_stage_model."}
         return utils.state_dict_prefix_replace(state_dict, replace_prefix)